Blog Archive

Αλέξανδρος Γ. Σφακιανάκης

Sunday, October 23, 2022

human monkeypox (hMPXV) re‐emergence: host immunity status and current vaccines landscape

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Monkeypox virus is a member of the Orthopoxvirus genus and the Poxviridae family. Orthopoxviruses are among the most intricate animal viruses. The pathogenicity of human monkeypox infection has been emphasized in response to its recent emergence in non-endemic countries and the threat of bioterrorism. It is always necessary to take appropriate precautions in exposure to emerging or re-emerging infections. Here, we focus on the current state of the human monkeypox infection outbreak, research & development of immunity responses and clinical interventions to prevent and treat human monkeypox virus and other human poxviruses.

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A minimally invasive method for titanium mesh fixation with resorbable sutures in guided bone regeneration: A retrospective study

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Objectives

Titanium mesh has become a mainstream choice for guided bone regeneration (GBR) owing to its excellent space maintenance. However, the traditional fixation method using titanium screws impacts surgery efficiency and increases patient trauma. We report a novel method of fixing a titanium mesh using resorbable sutures. We assessed the feasibility of resorbable sutures for fixing a titanium mesh and whether it can serve as a stable, universal, and minimally invasive fixation method for a broader application of titanium meshes.

Methods

Patients undergoing GBR with a digital titanium mesh fixed using titanium screws (TS group) and resorbable sutures (RS group) were observed at different time points. The stability of the fixation methods was evaluated on parameters such as titanium mesh spatial displacement, bone augmentation, and bone resorption.

Results

A total of 36 patients were included in this study. The exposure rate of the titanium mesh in the TS group was 16.67%, while no exposure was noted in the RS group. There was no significant difference in the parameters of titanium mesh spatial displacement, bone augmentation, and bone resorption between the two groups (p > 0.05).

Conclusion

The use of resorbable sutures for fixing a titanium mesh can achieve similar results to traditional fixation using titanium screws. Although this new fixation method can improve the efficiency of the surgery and reduce the risk of complications, the long-term clinical effects require further follow-up investigation.

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Do cone‐beam computed tomography low‐dose protocols affect the evaluation of the temporomandibular joint?

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

There is no established acquisition protocol based on scientific evidence for the acquisition of cone-beam computed tomography (CBCT) exams to evaluate the temporomandibular joint (TMJ).

Objectives

To evaluate the influence of acquisition protocols and jaw positioning on the diagnostic accuracy of TMJ condylar morphological alterations (CMA), dimension, position, and excursion.

Methods

Thirty-six TMJs on 18 dry skulls were imaged using a CBCT unit (OP300 Maxio, Instrumentarium, Tuusula, Finland) at two exposure settings (4.5 and 6.3 mA), three voxel resolutions (0.085, 0.125 and 0.280 mm), three jaw positions (concentric, anteriorized and posteriorized) and three jaw excursions (normoexcursion, hyperexcursion and hypoexcursion). The macroscopic anatomy examination and high-resolution CBCT images were used as ground truth for CMA. Twenty-five TMJs had at least one CMA with 11 healthy TMJs serving as controls. Three experienced oral and maxillofacial radiologists evaluated the parasagittal images for the presence of CMA, position, and excursion and measured dimensions. The area under the ROC curve, sensitivity, and specificity were calculated. Weighted Kappa (α=0.05) was used to determine intra- and inter-examiner reliability and comparisons between dependent variables analyzed by Analysis of Variance at an a prior level of significance of 0.05.

Results

The agreement of the evaluation of the position and excursion with the reference standard was high, independent of the protocol (range, 0.75-0.91). Various combinations of acquisition protocols and jaw position did not influence the CMA evaluation. Erosion was overdiagnosed in protocols with larger voxel sizes, and the detection of osteophytes greater in images with smaller voxel sizes. The anteroposterior dimension was greater in the open jaw position (p<0.05).

Conclusion

CBCT protocols using reduced radiation exposure from the CBCT machine evaluated in this study can be used to assess condylar morphology, dimension, position, and excursion, without compromising diagnostic performances for these parameters.

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Epigenetic upregulation of Schlafen11 renders WNT- and SHH- activated medulloblastomas sensitive to cisplatin

alexandrossfakianakis shared this article with you from Inoreader
Abstract
Background
Intensive chemotherapeutic regimens with craniospinal irradiation have greatly improved survival in medulloblastoma patients. However, survival markedly differs among molecular subgroups and their biomarkers are unknown. Through unbiased screening, we found Schlafen family member 11 (SLFN11), which is known to improve response to DNA damaging agents in various cancers, to be one of the top prognostic markers in medulloblastomas. Hence, we explored the expression and functions of SLFN11 in medulloblastoma.
Methods
SLFN11 expression for each subgroup was assessed by immunohistochemistry in 98 medulloblastoma patient samples and by analyzing transcriptomic databases. We genetically or epigenetically modulated SLFN11 expression in medulloblastoma cell lines and determined cytotoxic response to the DNA damaging agents cisplatin and topoisomerase I inhibitor SN-38 in vitro and in vivo.
Results
High SLFN11 expressing cases exhibited significantly longer survival than low expressing cases. SLFN11 was highly expressed in the WNT-activated subgroup and in a proportion of the SHH-activated subgroup. While WNT activation was not a direct cause of the high expression of SLFN11, a specific hypomethylation locus on the SLFN11 promoter was significantly correlated with high SLFN11 expression. Overexpression or deletion of SLFN11 made medulloblastoma cells sensitive and resistant to cisplatin and SN-38, respectively. Pharmacological upregulation of SLFN11 by the brain-penetrant histone deacetylase-inhibitor RG2833 markedly increased sensitivity to cisplatin and SN-38 in SLFN11-negative medulloblastoma cells. Intracranial xenograft studies also showed marked sensitivity to cisplatin by SLFN11-overexpression in medulloblastoma cells.
Conclusio ns
High SLFN11 expression is one factor which renders favorable outcomes in WNT-activated and a subset of SHH-activated medulloblastoma possibly through enhancing response to cisplatin.
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Saturday, October 22, 2022

Benzene Exposure From Selected Work Tasks on Offshore Petroleum Installations

alexandrossfakianakis shared this article with you from Inoreader
Abstract
Objectives
Work on offshore petroleum installations may cause exposure to benzene. Benzene is a carcinogenic agent, and exposure among workers should be as low as reasonably practicable. We aimed to assess short-term (less than 60 min) benzene exposure from the most frequent work tasks on offshore installations on the Norwegian continental shelf and identify determinants of exposure. In addition, we aimed to assess the time trend in task-based benzene measurements from 2002 to 2018.
Methods
The study included 763 task-based measurements with a sampling duration of less than 60 min, collected on 28 offshore installations from 2002 to 2018. The measurements were categorized into 10 different tasks. Multilevel mixed-effect Tobit regression models were developed for two tasks: sampling and disassembling/assembling equipment. Benzene source, season, indoors or outdoors, design of process area, year of production start, sampling meth od, and work operation were considered as potential determinants for benzene exposure in the models.
Results
The overall geometric mean (GM) benzene exposure was 0.02 ppm (95% confidence intervals 95%(CI: 0.01–0.04). The pipeline inspection gauge (PIG) operation task was associated with the highest exposure, with a GM of 0.33 ppm, followed by work on flotation cells, disassembling/assembling, and sampling, with GMs of 0.16, 0.04, and 0.01 ppm, respectively. Significant determinants for the disassembling/assembling task were work operation (changing or recertifying valves, changing or cleaning filters, and breaking pipes) and benzene source. For sampling, the benzene source was a significant determinant. Overall, the task-based benzene exposure declined annually by 10.2% (CI 95%: −17.4 to −2.4%) from 2002 to 2018.
Conclusions
The PIG operation task was associated with the highest exposure out of the ten tasks, followed by work on flotation cells and when perfo rming disassembling/assembling of equipment. The exposure was associated with the type of benzene source that was worked on. Despite the decline in task-based exposure in 2002–2018, technical measures should still be considered in order to reduce the exposure.
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Single-dose versus prolonged antibiotic prophylaxis for alveolar bone grafting in cleft patients

alexandrossfakianakis shared this article with you from Inoreader
This study compared the infection rate between prolonged and single-dose prophylaxis for this procedure, with the null hypothesis of no difference between the two groups. In total, 109 ABG procedures in 94 cleft patients performed by two surgeons were included. (Source: International Journal of Oral and Maxillofacial Surgery)
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Three-dimensional evaluation of condylar position after mandibular reconstruction with a fibula free flap —comparison of different surgical techniques

alexandrossfakianakis shared this article with you from Inoreader
Three-dimensional positional changes of the temporomandibular joint after mandible reconstruction using microvascular fibula flaps were investigated in 58 patients. The results of preoperative virtually planned surgery, intraoperative resection- and cutting-guided surgery, and non-guided surgery were compared. Pre- and postoperative computed tomography data of each patient were processed and superimposed digitally. The condyle deviations and rotations along the axes and planes of the skull, as well as Euclidean distances, were determined. (Source: International Journal of Oral and Maxillofacial Surgery)
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